31389863 has 2 divisors, whose sum is σ = 31389864. Its totient is φ = 31389862.

The previous prime is 31389847. The next prime is 31389893. The reversal of 31389863 is 36898313.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 31389863 - 2⁴ = 31389847 is a prime.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 31389863.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (31389823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15694931 + 15694932.

It is an arithmetic number, because the mean of its divisors is an integer number (15694932).

Almost surely, 2^31389863 is an apocalyptic number.

31389863 is a deficient number, since it is larger than the sum of its proper divisors (1).

31389863 is an equidigital number, since it uses as much as digits as its factorization.

31389863 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 93312, while the sum is 41.

The square root of 31389863 is about 5602.6657048230. The cubic root of 31389863 is about 315.4494733999.

The spelling of 31389863 in words is "thirty-one million, three hundred eighty-nine thousand, eight hundred sixty-three".